Generally, conventional nail polish compositions have a base composition of organic solvents containing a resin or primary film-forming agent, an aryl-sulfamide formaldehyde resin, or an alkyd resin, and a plasticizing agent. The resins are often ones including nitrocellulose, polyacrylates, styrene-acrylates, polyurethanes, polyester urethanes, and the like. These resins all have unwanted residual monomers or isocyanate residual and are used in combination with organic solvents to enable film formation.
In particular, nitrocellulose provides good adhesion of the compositions to nails upon application, and is the preferred conventional film-forming agent for use in nail polish compositions. Nitrocellulose, however, is highly flammable, and thus, may pose safety hazards during the manufacturing process for nail polish compositions that require the use of nitrocellulose. Additionally, the solvents used to dissolve nitrocellulose such as toluene, isopropanol, ethyl acetate, butyl acetate or mixtures thereof, are also flammable and have unpleasant odor. As such, alternatives to nitrocellulose, which provide good adhesion to nails but which avoid the negative issues associated with nitrocellulose, are sought to either reduce the amount of nitrocellulose used in the composition or entirely replace the nitrocellulose in the composition.
Other common components of nail polish such as formaldehyde, toluene and phthalate help provide a product that is long-lasting and fast drying. These components provide the nail polish with desirable attributes: toluene allows dilution of the resin and fast drying time of the polish, formaldehyde provides cross linking with keratin and offers good cohesion, and phthalate increases homogeneity of the film. However, the toxicity of these compounds is pushing cosmetic companies to identify alternative technologies while keeping the original attributes.
It has also been discovered that the use of aqueous-based nail polish compositions may help avoid the problems associated with conventional, organic solvent-based compositions. Aqueous compositions avoid much of the problem associated with non-aqueous compositions, such as, smell, toxicity to environment and damage to the nail. The problem with aqueous-based nail polish compositions, however, is that such compositions are generally slow to dry. Thus, such compositions would benefit from faster setting film-forming agents.
Therefore, there exists a need for new film-forming agents to be used in aqueous nail polish compositions which may reduce or replace the amount of organic solvents and nitrocellulose needed—providing a safer and more environmentally-friendly composition. Moreover, the resulting nail polish composition is preferably free of formaldehyde, toluene and phthalate. In aqueous-based compositions, such film-forming agents should be faster setting to help provide a nail polish composition that is not slow drying and still maintain good adhesion and glossiness.